Field of the Invention
The disclosure generally relates to the tool traps. Specifically, the disclosure relates to tool traps for valves restricting the debris from falling downhole.
Description of the Related Art
After oil/gas wells are drilled and completed, a wellhead remains on the well connected with its tubing annulus and casing annulus. The wellhead allows selective pressurization or depressurization of them for safety reasons and/or to allow various services to be performed within the well. Wellheads comprise valves having ID's slightly greater than the tubing ID, which are mounted vertically to open and close the bore of the center-most pipe string generally known as the tubing. The tubing extends down to the production zone to convey the oil and/or gas to the surface. During a typical well's producing life, various services such as plugging, logging, running special tools in or out, latching and unlatching down-hole devices. These services are most often done by running tools down-hole on wire-lines, supported by related equipment such as tool traps that prevent unwanted objects from falling down-hole.
A conventional tool trap is disclosed in columns 2-4 of U.S. Pat. No. 3,435,895 and shown in FIGS. 2 and 3, having the following members most pertinent to the present application: body 10; movable gate 11; gate opening means annular hydraulic piston 14; springs 18a and 18b to automatically close the gate after upward passage of a tool, if there is no fluid pressure on the piston. Although numerous Tool Traps are marketed today, they appear to have only one substantial improvement over the '895 patent, that is, an extension of the '895 patent's hinge pin 12 through the body wall 10 to allow independent manual opening and closing of the gate. No prior art known even addresses: debris falling on top of the gate that prevents opening of the gate; accumulation of debris around the gate that prevents closing of the gate; or prevention of debris falling down-hole that may prevent tools from working properly. Most Tool Traps of the prior art have little or no area around the bore for debris to accumulate and no known Tool Traps have means to prevent debris from falling downhole where it may foul workings of the wire-line tools.
Therefore, there remains a need for an improved tool trap to accommodate unwanted debris.